Display unit, method of manufacturing display unit, and electronic apparatus

ABSTRACT

A display unit includes a plurality of pixels, a reflector layer, and an auxiliary electrode. Each of the plurality of pixels has a first electrode, an organic layer, and a second electrode in this order. The organic layer and the second electrode are provided on the first electrode. The organic layer includes a light-emitting layer. The reflector layer has a light-reflecting surface around each of the pixels. The auxiliary electrode is provided on the reflector layer and is projected from an upper end of the light-reflecting surface. The auxiliary electrode has a portion which is exposed from the organic layer, and the exposed portion is covered with the second electrode.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/682,135, filed on Nov. 13, 2019, which is a continuation ofU.S. patent application Ser. No. 16/369,307, filed on Mar. 29, 2019,which is a continuation of U.S. patent application Ser. No. 15/512,572,filed on Mar. 19, 2017, which is a U.S. National Phase of InternationalPatent Application No. PCT/JP2015/076244, filed on Sep. 16, 2015, andwhich claims priority benefit of Japanese Patent Application No. JP2014-208116 filed in the Japan Patent Office on Oct. 9, 2014. Each ofthe above-referenced application is hereby incorporated herein byreference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a display unit such as an organicelectroluminescence unit, a method of manufacturing the display unit,and an electronic apparatus including the display unit.

BACKGROUND ART

Recently, display units with use of an organic electroluminescence (EL)device (organic EL displays) have been increasingly developed. Thedisplay units are roughly classified into top surface emission (topemission) display units and bottom surface emission (bottom emission)display units.

In the top surface emission display unit, an upper electrode (e.g.,cathode) on light extraction side is typically configured by atransparent electrically conductive film such as indium-tin oxide (ITO),thus causing resistance (cathode resistance) to be high. As a result, avoltage is dropped (occurrence of so-called voltage drop) at a middleportion of a panel, causing an increase in power consumption as well asdeterioration of image quality. In this case, use of metal for the upperelectrode enables the resistance to be lowered; however, metal has poorlight-transmissivity. Thus, the use of metal for the upper electrodereduces light extraction efficiency, causing luminance to be lowered.

In addition, in order to lower the cathode resistance, a method may beadopted in which the transparent electrically conductive film isprovided immediately on the organic electroluminescence device. However,the transparent electrically conductive film typically has a highresistance value in a thin film, and thus may desirably have increasedthickness in order to lower the resistance value. When the transparentelectrically conductive film has increased thickness, however, thelight-transmissivity is lowered, leading to lowered luminance. Asdescribed, it is not easy for the upper electrode to both achievelight-transmissivity and electrical conductivity.

Furthermore, in order to improve the light extraction efficiency forenhancement of luminance, there has been proposed a device structurewith use of a so-called anode reflector (e.g., PTL 1). Morespecifically, a structure body having such a sloped plane as to surrounda pixel aperture is formed with use of a material having a predeterminedrefraction index.

CITATION LIST Patent Literature

PTL 1: Japanese Unexamined Patent Application Publication No.2013-191533

SUMMARY OF INVENTION

In the method using the reflector as in the above-described PTL 1,however, the upper electrode has film thickness that is decreased on thesloped plane of the structure body, making the resistance value likelyto increase. In the case of using the reflector, the cathode resistanceis particularly likely to be high as described above, for which animprovement is desired.

It is therefore desirable to provide a display unit that allows forreduction in power consumption while improving luminance, a method ofmanufacturing the display unit, and an electronic apparatus.

A display unit according to an embodiment of the present disclosureincludes a plurality of pixels, a reflector layer, and an auxiliaryelectrode. Each of the plurality of pixels has a first electrode, anorganic layer, and a second electrode in this order. The organic layerand the second electrode are provided on the first electrode. Theorganic layer includes a light-emitting layer. The reflector layer has alight-reflecting surface around each of the pixels. The auxiliaryelectrode is provided on the reflector layer and is projected from anupper end of the light-reflecting surface. The auxiliary electrode has aportion which is exposed from the organic layer, and the exposed portionis covered with the second electrode.

A method of manufacturing a display unit according to an embodiment ofthe present disclosure includes: forming a plurality of pixels eachhaving a first electrode, an organic layer, and a second electrode inthis order, the organic layer and the second electrode being provided onthe first electrode, the organic layer including a light-emitting layer;forming a reflector layer, the reflector layer having a light-reflectingsurface around each of the pixels; and forming, on the reflector layer,an auxiliary electrode that is projected from an upper end of thelight-reflecting surface. The organic layer and the second electrode areformed after the forming of the reflector layer and the auxiliaryelectrode.

An electronic apparatus according to an embodiment of the presentdisclosure includes the display unit according to the embodiment of thepresent disclosure.

According to the display unit and the electronic apparatus of theembodiments of the present disclosure, the efficiency of extractinglight emitted from the organic layer is improved by the reflector layerhaving a light-reflecting surface. Further, the auxiliary electrode isprovided on the reflector layer and is projected from the upper end ofthe light-reflecting surface. In addition, a portion of the auxiliaryelectrode is exposed from the organic layer, and the exposed portion iscovered with the second electrode. This secures electrical connectionbetween the auxiliary electrode and the second electrode.

According to the method of manufacturing the display unit according tothe embodiment of the present disclosure, the organic layer is formedafter the formation of the reflector layer and the auxiliary electrodethat is projected from the upper end of the light-reflecting surface ofthe reflector layer. This causes the auxiliary electrode to divide(disconnect) the organic layer, and thus a portion of the auxiliaryelectrode is exposed from the organic layer. The exposed portion iscovered with the second electrode to secure the electrical connectionbetween the auxiliary electrode and the second electrode.

According to the display unit, the method of manufacturing the displayunit, and the electronic apparatus according to the embodiments of thepresent disclosure, the reflector layer makes it possible to improve thelight extraction efficiency. Further, providing the auxiliary electrodeto be projected from the upper end of the light-reflecting surface ofthe reflector layer makes it possible to secure the electricalconnection between the auxiliary electrode and the second electrode.This makes it possible to lower a resistance value in the secondelectrode without increasing the film thickness of the second electrode,i.e., without reducing light-transmissivity. Thus, it becomes possibleto reduce power consumption while improving luminance.

It is to be noted that that the contents described above are mereexamples. The effects of the present disclosure are not limited to thosedescribed above, and may be other different effects, or may furtherinclude other effects in addition to the effects described above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a configuration of a display unit according to afirst embodiment of the present disclosure.

FIG. 1B illustrates an example of a pixel drive circuit illustrated inFIG. 1.

FIG. 2 is a cross-sectional view of the configuration of the displayunit illustrated in FIG. 1.

FIG. 3 is an enlarged cross-sectional view of a portion of FIG. 2.

FIG. 4A illustrates a schematic plan view of an example of an auxiliaryelectrode and a reflector layer illustrated in FIG. 2.

FIG. 4B illustrates a schematic plan view of another example of theauxiliary electrode and the reflector layer illustrated in FIG. 2.

FIG. 5A is a cross-sectional view for describing a method ofmanufacturing the display unit illustrated in FIG. 2.

FIG. 5B is a cross-sectional view of a step subsequent to FIG. 5A.

FIG. 5C is a cross-sectional view of a step subsequent to FIG. 5B.

FIG. 5D is a cross-sectional view of a step subsequent to FIG. 5C.

FIG. 5E is a cross-sectional view of a step subsequent to FIG. 5D.

FIG. 5F is a cross-sectional view of a step subsequent to FIG. 5E.

FIG. 5G is a cross-sectional view of a step subsequent to FIG. 5F.

FIG. 5H is a cross-sectional view of a step subsequent to FIG. 5G.

FIG. 5I is a cross-sectional view of a step subsequent to FIG. 5H.

FIG. 6A is a simulation diagram for describing an effect brought by areflector layer.

FIG. 6B is a simulation diagram for describing an effect brought by areflector layer.

FIG. 7A is a perspective view of a configuration of a smartphone.

FIG. 7B is a perspective view of a configuration of the smartphone.

FIG. 8 is a perspective view of a configuration of a tablet personalcomputer.

FIG. 9 is a perspective view of a configuration of a television.

FIG. 10A is a plan view of a configuration of a mobile phone.

FIG. 10B is a plan view of a configuration of the mobile phone.

FIG. 11A is a front view of a configuration of a digital single-lensreflex camera.

FIG. 11B is a rear view of a configuration of the digital single-lensreflex camera.

FIG. 12 is a perspective view of a configuration of a head-mounteddisplay.

FIG. 13A is a front view of a configuration of a digital still camera.

FIG. 13B is a rear view of a configuration of the digital still camera.

FIG. 14 is a perspective view of a configuration of a notebook personalcomputer.

FIG. 15 is a perspective view of a configuration of a video camera.

DESCRIPTION OF THE EMBODIMENTS

Some embodiments of the disclosure are described in detail below in thefollowing order with reference to drawings.

1. Embodiment (An example of display unit including, on a reflectorlayer, an auxiliary electrode that is projected from a light-reflectingsurface of the reflector layer)2. Application Examples (Examples of electronic apparatuses)

Embodiment Configuration

FIG. 1A illustrates a configuration of a display unit (display unit 1)according to an embodiment of the present disclosure. The display unit 1may be an organic EL display. In a display region 110A on a firstsubstrate 11, a plurality of pixels 10R, 10G, and 10B each including anorganic EL device 10 may be disposed in matrix. The pixels 10R, 10G, and10B emit, respectively, red light LR (wavelength of 620 nm to 750 nmboth inclusive), green light LG (wavelength of 495 nm to 570 nm bothinclusive), and blue light LB (wavelength of 450 nm to 495 nm bothinclusive). The pixels 10R, 10G, and 10B may correspond to subpixels (Rpixel, G pixel, and B pixel); for example, a combination of the R pixel,the G pixel, and the B pixel may be adopted as one pixel to performimage display. On the periphery of the display region 110A, there may beprovided a signal line drive circuit 120 and a scanning line drivecircuit 130 for image display.

An active drive circuit (pixel circuit 140), for example, may beprovided inside the display region 110A. As illustrated in FIG. 1B, thepixel circuit 140 may include a drive transistor Tr1 and a writetransistor Tr2, and a capacitor Cs may be provided between thesetransistors Tr1 and Tr2. The organic EL device 10 may be coupled inseries to the drive transistor Tr1 between a first power supply line(Vcc) and a second power supply line (GND). The signal line drivecircuit 120 may supply an image signal to source electrodes of therespective transistors Tr2 thorough a plurality of signal lines 120Aarranged in a column direction. The scanning line drive circuit 130 maysupply a scanning signal sequentially to gate electrodes of therespective transistor Tr2 thorough a plurality of scanning lines 130Aarranged in a row direction.

FIG. 2 illustrates a cross-sectional configuration of the display unit 1illustrated in FIG. 1A. It is to be noted that FIG. 2 illustratesregions corresponding to the respective pixels 10R, 10G, and 10B. Theorganic EL device 10 may be provided between the first substrate 11 anda second substrate 22. The above-described pixel circuit 140 may beprovided on the first substrate 11, and a flattening layer 13 may be soprovided as to cover the pixel circuit 140. On the flattening layer 13,there may be provided a first electrode 14 as an anode, for example. Thefirst electrode 14 may be electrically coupled to the transistor Tr1provided in the pixel circuit 140. FIG. 2 illustrates only a thin filmtransistor (TFT) 12 corresponding to the transistor Tr1, among the pixelcircuit 140.

The organic EL device 10 may have a configuration in which the firstelectrode 14, an organic layer 16 including a light-emitting layer, anda second electrode 18 as a cathode, for example, are stacked in orderfrom first substrate 11 side. The second substrate 22 may be joined ontothe organic EL device 10, with a protective layer 19 and a sealing layer20 being provided therebetween. On a surface, of the second substrate22, which faces the first substrate 11, there may be provided a colorfilter layer 21 including a red filter 21R, a green filter 21G, a bluefilter 21B, and a black matrix layer BM.

The display unit 1 may be, for example, a so-called top emission (topsurface emission) organic EL display in which light generated in theorganic layer 16 is extracted from second electrode 18 side. The organiclayer 16 may have a layered structure which is common to the pixels 10R,10G, and 10B. For example, the organic layer 16 may include a pluralityof light-emitting units, and may be configured to emit white light as awhole. The white light emitted from each of the organic EL devices 10may pass through the color filter layer 21, thus causing the red lightLR, the green light LG, and the blue light LB to be emitted.Configurations of respective components are described below.

The first substrate 11 may be made of, for example, glass, a silicon(Si) wafer, a resin, or an electrically conductive substrate. Examplesof available electrically conductive substrates may include a substratewhose surface is insulated with silicon oxide (Sift) or a resin, forexample.

The TFT 12 may be, for example, a bottom gate thin film transistor(TFT), and may be configured by a metal oxide semiconductor field effecttransistor (MOSFET), for example. In the TFT 12, for example, a gateelectrode, a gate insulating film, a semiconductor thin film that formsa channel, and an interlayer insulating film may be stacked in thisorder on the first substrate 11; a source electrode and a drainelectrode may be provided to be electrically coupled to thesemiconductor thin film. The first electrode 14 may be electricallycoupled to the drain electrode, for example, of the TFT 12. It is to benoted that the TFT 12 is not limited to such a bottom gate TFT; the TFT12 may also be a top gate TFT. Further, the semiconductor thin film mayalso be made of, for example, a crystalline silicon or an amorphoussilicon. Alternatively, the semiconductor thin film may also be made ofan oxide semiconductor.

The flattening layer 13 may be provided for flattening the surface ofthe first substrate 11 on which the TFT 12 is provided to allow therespective layers of the organic EL device 10 to have a uniform filmthickness. The flattening layer 13 may have a contact hole forelectrically coupling the first electrode 14 to the drain electrode ofthe TFT 12, and thus may also serve to prevent the first electrode 14from being brought into contact with the TFT 12 unnecessarily. Examplesof the material for forming the flattening layer 13 may include anorganic material such as a polyimide resin, an acrylic resin, and anovolac resin; and an inorganic material such as silicon oxide (SiO₂),silicon nitride (SiN_(x)), and silicon oxynitride (SiON).

The first electrode 14 may be provided for each pixel, and may functionas an electrode that injects holes, for example, into the organic layer16. The first electrode 14 may have light reflectivity, and maydesirably have as high reflectance as possible in terms of enhancinglight-emitting efficiency. Examples of the material for forming thefirst electrode 14 may include a metal simple substance such as silver(Ag), aluminum (Al), molybdenum (Mo), and chromium (Cr), and an alloythereof. Further, the first electrode 14 may be either a monolayer filmcontaining the above-mentioned metal simple substance or the alloy, or alayered film.

The organic layer 16 may include, in addition to the light-emittinglayer, a hole transport layer (HTL), a hole injection layer (HIL), andan electron transport layer (ETL), for example. Further, the organiclayer 16 may have a so-called tandem structure in which a plurality oflight-emitting layers having different emission colors are stacked.Mixture of color light beams emitted from a plurality of stackedlight-emitting layers allows for obtainment of a desired emissionspectrum (e.g., white color). Examples of such a tandem structure mayinclude a tandem structure in which a blue-light-emitting layer and ayellow-light-emitting layer are stacked, and a tandem structure in whicha red-light-emitting layer, a green-light-emitting layer, and ablue-light-emitting layer are stacked. The organic layer 16 may beprovided across the entire region of the display region 110A of thefirst substrate 11. Strictly speaking, however, the organic layer 16 maybe divided at a portion of the auxiliary electrode 17; the organic layer16 and an organic layer 16 a may be provided, respectively, on the firstelectrode 14 and the auxiliary electrode 17. Further, while thedescription is given here of an example of the case where the organiclayer 16 includes a plurality of stacked layers and emits white light bycolor mixture, the organic layer 16 may also be configured to include asingle light-emitting layer (i.e., the organic layer 16 may performsingle color emission).

The second electrode 18 may have light-transmissivity, and, for example,may be provided across the entire surface of the display region 110A soas to be common to all of the pixels 10R, 10G, and 10B. The secondelectrode 18 may be made of one or more of indium-tin oxide (ITO),indium-zinc oxide (IZO), titanium oxide (TiO), indium-gallium-zinc oxide(IGZO), zinc oxide (ZnO), aluminum-added zinc oxide (AZO), fluorine(F)-added zinc oxide (ZnO:F), fluorine-added tin oxide (FTO), andfluorine-added silicon oxide (SiO₂:F), for example. Alternatively, asthe second electrode 18, a metal simple substance of, for example,aluminum (Al), copper (Cu), magnesium (Mg), and silver (Ag), or an alloythereof may be used. The second electrode 18 may be formed by asputtering method or an atomic layer deposition method, for example.

The protective layer 19 may be made of, for example, silicon nitride,silicon oxide, or a metal oxide. The sealing layer 20 may be made of,for example, a thermosetting resin or an ultraviolet-curable resin, andmay function as a bonding layer.

The second substrate 22 may be made of a material such as glasstransparent to respective color light beams generated in the pixels 10R,10G, and 10B.

In the color filter layer 21, the black matrix layer BM with alight-shielding property may have apertures which face the respectiveorganic EL devices 10. The red filter 21R, the green filter 21G, and theblue filter 21B may be provided in the respective apertures of the blackmatrix layer BM. The red filter 21R selectively transmits red light. Thegreen filter 21G selectively transmits green light. The blue filter 21Bselectively transmits blue light. The color filter layer 21 may beprovided on either surface, of the second substrate 22, on lightincident side (device side) or on light emission side; however, in thisexample, the color filter layer 21 is provided on the surface on thelight incident side, for example. It is to be noted that, although thedescription is given here of an example of the configuration in whichthe black matrix layer BM is provided in the color filter layer 21, theblack matrix layer BM may not be necessarily provided.

(Reflector Layer 15)

The display unit 1 may further have a reflector structure (so-calledanode reflector) in the above-described configuration. That is, areflector layer 15 having a light-reflecting surface (surface Tdescribed later) may be provided around each pixel. In the presentembodiment, the auxiliary electrode 17 is provided on the reflectorlayer 15.

FIG. 3 illustrates a portion of FIG. 2 in an enlarged manner. In detail,the reflector layer 15 may have the light-reflecting surface (surface T)so as to surround each of the organic EL devices 10 (i.e., pixels 10R,10G, and 10B). In other words, the reflector layer 15 may have a recess15A to face each pixel, and may have a protrusion 15B at a regionbetween the organic EL devices 10 (i.e., between pixels). The reflectorlayer 15 may be made of, for example, a material having a low refractiveindex such as silicon oxide (SiO₂), magnesium fluoride (MgF₂), lithiumfluoride (LiF), a polyimide resin, an acrylic resin, a fluorine resin, asilicone resin, a fluorine-based polymer, or a silicon-based polymer.Such a configuration allows light emitted from the organic layer 16 tobe reflected upward at the surface T of the recess 15A (protrusion 15B).The overall shape of the recess 15A may be, for example, an invertedtruncated cone shape (circular shape in a plan view). It is to be notedthat another material having a different refractive index may beembedded in the recess 15A. Further, surfaces of the recess 15A and theprotrusion 15B may be covered with a film made of yet another materialhaving a different refractive index. Furthermore, the recess 15A mayhave a rounded shape, in cross section, such as mortar, for example.

(Auxiliary Electrode 17)

The auxiliary electrode 17 is provided on the reflector layer 17(adjacent to the protrusion 15B). The auxiliary electrode 17 is providedsuch that a portion of the auxiliary electrode 17 is projected (toward acenter of the pixel) from an upper end E1 of the surface T. In otherwords, the upper end E1 of the surface T may be disposed at a positionrecessed from an end surface (inner surface of an aperture H describedlater) 17 a of the auxiliary electrode 17. Width B of the projectedportion of the auxiliary electrode 17 may be set to have a proper sizesuch that the organic layer 16 is divided (disconnected) in amanufacturing process described later, taking into considerationthickness of the organic layer 16, thickness of the auxiliary electrode17, thickness of the reflector layer 15, and pixel size. The width B maybe adjusted depending on an etching condition when forming the reflectorlayer 15. Examples of the material for forming the auxiliary electrode17 may include a metal containing one or more of titanium (Ti),molybdenum (Mo), copper (Cu), and aluminum (Al), for example.Alternatively, it is also possible to use, as the auxiliary electrode17, a transparent electrically conductive film containing one or more ofindium-tin oxide (ITO), titanium oxide (TiO), indium-zinc oxide (IZO),indium-gallium-zinc oxide (IGZO), zinc oxide (ZnO), aluminum-added zincoxide (AZO), fluorine (F)-added zinc oxide (ZnO:F), fluorine-added tinoxide (FTO), and fluorine-added silicon oxide (SiO₂:F), for example.

Due to such a configuration of the auxiliary electrode 17, a portion ofthe auxiliary electrode 17 (more specifically, a lower surface of theprojected portion of the auxiliary electrode 17; a portion C1 in FIG. 3)is exposed from the organic layer 16. The exposed portion C1 is coveredwith the second electrode 18. The auxiliary electrode 17 and the secondelectrode 18 may be electrically coupled to each other at the portionC1. It is to be noted that the organic layer 16 a that is separatedelectrically from the organic layer 16 may be provided on the auxiliaryelectrode 17. The organic layer 16 a may be deposited on the auxiliaryelectrode 17 when the organic layer 16 is formed, and may be made of thesame material as that of the organic layer 16.

FIG. 4A illustrates an example of a planar arrangement (arrangement on aplane parallel to a principal plane of the first substrate 11) of theauxiliary electrode 17 and the reflector layer 15. In this manner, therecess 15A may have, for example, a circular shape in a plan view. Morespecifically, a planar shape formed by the upper end E1 (planar shape onupper end E1 side) S1 of the recess 15A (surface T) and a planar shapeformed by a lower end E2 (planar shape on lower end E2 side) S2 thereofmay each have a circular shape. The auxiliary electrode 17 may have theaperture H to face the recess 15A. The aperture shape of the aperture Hmay be substantially similar to the planar shape Si of the recess 15A,and may be smaller than the planar shape S1. In this example, theaperture shape of the aperture H has a circular shape with a smallerdiameter than that of the planar shape S1. The organic layer 16 may bein contact with the first electrode 14 on the lower end E2 side of therecess 15A. That is, a region corresponding to the planar shape S2 mayserve as a region that contributes to light emission (pixel aperture).The auxiliary electrode 17 and the recess 15A may be provided for eachpixel. As for the arrangement, the auxiliary electrode 17 and the recess15A may be arranged in matrix in two orthogonal directions asillustrated in FIG. 4A, for examples, depending on the layout of thepixels 10R, 10G, and 10B. However, as illustrated in FIG. 4B, forexample, an arrangement may also be adopted in which a portion of a rowor column may be shifted in one direction with reference to thearrangement of FIG. 4A.

It is to be noted that, in this example, the circular shape is adoptedas examples of the aperture shape of the aperture H of the auxiliaryelectrode 17 and the planar shape of the recess 15A of the reflectorlayer 15; however, other various shapes may be adopted in addition tothe circular shape. For example, either an ellipsoidal shape or apolygonal shape such as a rectangular shape or a hexagonal shape mayalso be adopted. Further, an asymmetric shape or a shape having both acurve and a straight line may also be adopted. Furthermore, the shapeand size of each of the aperture H and the recess 15A either may be thesame among the pixels 10R, 10G, and 10B, or may be different for each ofthe pixels 10R, 10G, and 10B (for each of emission colors).

[Manufacturing Method]

The display unit 1 as described above may be manufactured, for example,as described below. FIGS. 5A to 5I are schematic diagrams for describinga method of manufacturing the display unit 1 of the present embodiment.

First, as illustrated in FIG. 5A, the pixel circuit 140 including theTFT 12 (only the TFT 12 is illustrated here) may be formed on the firstsubstrate 11. For example, the gate electrode, the gate insulating film,the semiconductor layer, the interlayer insulating film, the sourceelectrode, and the drain electrode may be formed using a known thin filmprocess.

Subsequently, as illustrated in FIG. 5B, the flattening layer 13 may beformed to cover the TFT 12, for example, on the first substrate 11, andthereafter a contact hole 13 a may be formed at a position correspondingto the drain electrode, for example, of the TFT 12.

(Formation of First Electrode 14)

Next, as illustrated in FIG. 5C, the first electrode 14 may be formed onthe flattening layer 13. More specifically, the above-mentioned metalmaterial may be formed on the flattening layer 13 by the vapordeposition method or the sputtering method, for example. Thereafter,etching using a photolithography method, for example, may be adopted toperform patterning for each pixel, thus forming the first electrode 14.The first electrode 14 may be electrically coupled to the TFT 12 throughthe contact hole 13 a.

(Formation of Reflector Layer 15 and Auxiliary Electrode 17)

Thereafter, as illustrated in FIG. 5D, the material having theabove-described refractive index (e.g., reflector material 150 made ofSiO_(x)) may be formed on the first electrode 14 across the entiresurface of the first substrate 11 by the vapor deposition method or thesputtering method, for example.

Subsequently, the auxiliary electrode 17 made of the above-mentionedelectrically conductive material may be formed on the reflector material150. More specifically, as illustrated in FIG. 5E, the above-mentionedelectrically conductive material (e.g., titanium) may be formed on thereflector material 150 by the sputtering method, for example.Thereafter, as illustrated in FIG. 5F, the auxiliary electrode 17 may bepatterned by etching using the photolithography, for example, to form aplurality of apertures H. In this case, the apertures H may be formed atpositions corresponding to the respective first electrodes 14.

Next, as illustrated in FIG. 5G, the reflector material 150 may bepatterned to form the reflector layer 15. More specifically, isotropicetching may be performed on the reflector material 150 using theauxiliary electrode 17 as a mask. This allows for selective removal ofregions facing the respective apertures H of the auxiliary electrode 17.The reflector layer 15 may be formed which has the recess 15A and theprotrusion 15B, respectively, on the first electrode 14 and at a regionbetween the pixels. Further, the isotropic etching may allow theauxiliary electrode 17 to be formed in such a manner to be projectedfrom the upper end E1 of the surface T (i.e., such that the upper end E1of the surface T is disposed at a position recessed from the end surface17 a of the auxiliary electrode 17).

(Formation of Organic Layer 16)

Thereafter, as illustrated in FIG. 5H, the organic layer 16 may beformed. More specifically, an organic material may be formed (deposited)continuously across the entire region of the substrate 11 by a vacuumvapor deposition method, for example. Here, film formation by the vacuumvapor deposition method leads to relatively poor coverage, and isunlikely to go around below (rear side of) the projected portion of theauxiliary electrode 17. As a result, the organic layer 16 may be dividedand deposited near the end surface 17 a of the auxiliary electrode 17,and the portion (lower surface portion C1 of the projected portion) ofthe auxiliary electrode 17 may be exposed from the organic layer 16.Further, the organic layer 16 a may be so deposited as to cover theupper surface of the auxiliary electrode 17.

(Formation of Second Electrode 18)

Subsequently, as illustrated in FIG. 5I, the second electrode 18 made ofthe above-mentioned material may be formed using the sputtering methodor the atomic layer deposition (ALD) method, for example. Here, filmformation by the sputtering method or the ALD method leads to relativelyfavorable coverage, and thus the second electrode 18 is likely to goaround also below the projected portion of the auxiliary electrode 17.As a result, the second electrode 18 may also attach to the portion C1exposed from the organic layer 16 to cover the portion C1, thuscompleting the film formation. This secures electrical connectionbetween the auxiliary electrode 17 and the second electrode 18.

Lastly, although illustration is omitted, the protective layer 19 may beformed on the second electrode 18, and thereafter the second electrode22 on which the color filter layer 21 is formed may be joined to thesecond electrode 18 on which the protective layer 19 is formed with thesealing layer 20 being provided therebetween. Through these steps, thedisplay unit 1 illustrated in FIG. 2 may be completed.

Function and Effect

As illustrated in FIGS. 1A and 1B, in the display unit 1, a scanningsignal may be supplied from the scanning line drive circuit 130 to thegate of the transistor Tr2 of each of the pixels 10R, 10G, and 10B, andan image signal may be supplied from the signal line drive circuit 120through the transistor Tr2 to a holding capacitor Cs and held therein.Depending on the signal held in the holding capacitor Cs, the transistorTr1 (TFT 12) may be ON/OFF controlled, thereby causing a drive currentId to be injected into the organic EL device 10 of each of the pixels10R, 10G, and 10B. The drive current Id may be injected into thelight-emitting layer of the organic layer 16 through the first electrode14 and the second electrode 18, thus causing holes and electrons to berecombined to cause light emission.

When white light beams are generated from the respective organic ELdevices 10, the respective white light beams may be transmitted through,for example, the second electrode 18 and the protective layer 19, andthereafter may be transmitted through any of the red filter 21R, thegreen filter 21G, and the blue filter 21B of the color filter layer 21.This may cause the respective white color beam to be converted to thered color LR, the green light LG, and the blue light LB to be emittedupward above the second electrode 22. In this manner, the display unit 1performs image display by top surface emission.

Further, in the present embodiment, a reflector layer 15 may be providedas an anode reflector. This may cause at least a portion of lightemitted from the organic layer 16 to be reflected upward (upwardobliquely) as illustrated in FIG. 6A, for example, thus improving lightextraction efficiency. As a result, luminance (front luminance) isimproved. Furthermore, the reflector layer 15 and the auxiliaryelectrode 17 may serve as a wall between the pixels, thus making itpossible to prevent a light beam from leaking into an adjacent pixel,which allows for suppression of color mixing. It is to be noted that,when such a reflector layer 15 is not provided, emission light mayradiate in a wider range as illustrated in FIG. 6B, for example, causinga light beam to be leaked into an adjacent pixel, for example, thusleading to decreased luminance or lowered image quality.

In contrast, in the case of the top surface emission, alight-transmissive transparent electrically conductive film is used asthe upper electrode (corresponding to the second electrode 18) on lightextraction side, thus causing the resistance value (cathode resistance)to be increased, causing a so-called voltage drop to be likely to occur.This undesirably leads to increased power consumption or deteriorationin image quality.

As opposed thereto, in the present embodiment, the auxiliary electrode17 is provided on the reflector layer 15. The auxiliary electrode 17 isprojected from the upper end of the surface T of the reflector layer 15,and a portion (portion C1) of the projected portion is exposed from theorganic layer 16. The portion C1 is covered with the second electrode18. This secures electrical connection between the auxiliary electrode17 and the second electrode 18. As a result, a resistance value in thesecond electrode 18 is reduced.

As has been described above, according to the present embodiment,providing the reflector layer 15 makes it possible to improve the lightextraction efficiency, thus improving luminance. Further, providing, onthe reflector layer 15, the auxiliary electrode 17 to be projected fromthe upper end of the surface T makes it possible to secure electricalconnection between the auxiliary electrode 17 and the second electrode18. Here, the transparent electrically conductive film used for thesecond electrode 18 has a tendency to reduce light-transmissivity due toincreased film thickness. Further, metal has excellent electricalconductivity, but has poor light-transmissivity. In the presentembodiment, it is not necessary to increase the film thickness of thetransparent electrically conductive film or to use metal as the secondelectrode 18 in order to lower the resistance value of the secondelectrode 18. In other words, it becomes possible to suppress voltagedrop without reducing light-transmissivity. Thus, it becomes possible toreduce power consumption while improving luminance.

APPLICATION EXAMPLES

The display unit described in the foregoing embodiment and modificationexample is applicable to electronic apparatuses in any fields thatdisplay, as an image, an image signal input from outside or an imagesignal generated inside. The display unit described herein isparticularly suitable for small-sized to mid-sized electronicapparatuses. The followings illustrate examples thereof.

FIGS. 7A and 7B illustrate outer appearances of a smartphone 220. Thesmartphone 220 may include, for example, a display section 221 and anoperation section 222 on front side, and a camera 223 on rear side; thedisplay unit 1 of the foregoing embodiment may be mounted on the displaysection 221.

FIG. 8 illustrates an outer appearance of a tablet personal computer240. The tablet personal computer 240 may include, for example, a touchpanel section 241 and a casing 242; the display unit 1 of the foregoingembodiment may be mounted on the touch panel section 241.

FIG. 9 illustrates an outer appearance of a television 250. Thetelevision 250 may include, for example, a main body section 251 and astand 252. The display unit 1 according to the foregoing embodiment maybe mounted on the main body section 251.

FIGS. 10A and 10B illustrate outer appearances of a mobile phone 290.The mobile phone 290 may include, for example, an upper casing 291 and alower casing 292 joined together with a joining section (hinge section)293, and may further include a display 294, a sub-display 295, a picturelight 296, and a camera 297. The display unit 1 according to theforegoing embodiment may be mounted on the display 294 or thesub-display 295.

FIGS. 11A and 11B illustrate outer appearances of a digital single-lensreflex camera 410. The digital single-lens reflex camera 410 mayinclude, for example, a main body 411, a lens 412, a grip 413, a displaysection 414, and a view finder 415. The display unit 1 according to theforegoing embodiment may be mounted on the display section 414 or theview finder 415.

FIG. 12 illustrates an outer appearance of a head-mounted display 420.The head-mounted display 420 may include, for example, a glass-shapeddisplay section 421 and a support section 422. The display unit 1according to the foregoing embodiment may be mounted on the displaysection 421.

FIGS. 13A and 13B illustrate outer appearances of a digital still camera520. The digital still camera 520 may include, for example, aflashlight-emitting section 521, a display section 522, a menu switch523, and a shutter button 524. The display unit 1 according to theforegoing embodiment may be mounted on the display section 522.

FIG. 14 illustrates an outer appearance of a notebook personal computer530. The notebook personal computer 530 may include, for example, a mainbody 531, a keyboard 532 for operation of inputting characters, forexample, and a display section 533 for displaying an image. The displayunit 1 according to the foregoing embodiment may be mounted on thedisplay section 533.

FIG. 15 illustrates an outer appearance of a video camera 540. The videocamera 540 may include, for example, a main body 541, a subject-shootinglens 542 provided on a front side surface of the main body 610, ashooting start/stop switch 543 and a display section 544. The displayunit 1 according to the foregoing embodiment may be mounted on thedisplay section 544.

Although description has been given of the embodiment, the disclosure isby no means limited to the foregoing embodiment and the applicationexamples, and various modifications are possible. For example, the shapeand the arrangement of the auxiliary electrode 17 are not limited tothose described above, and various other configurations may be adopted.Although the foregoing embodiment and the application examples exemplifythe case where the aperture shape of the aperture H of the auxiliaryelectrode 17 is substantially similar to the planar shape Si of therecess 15A of the reflector layer 15 in a plan view; however, theseshapes may not be necessarily similar. It is sufficient for theauxiliary electrode to be formed to be projected from the upper end ofthe light-reflecting surface of the reflector layer; the aperture shapeof the auxiliary electrode is not particularly limited. Further,although a single auxiliary electrode may be provided, a plurality ofauxiliary electrodes may also be provided. However, when the reflectorlayer 15 is formed by etching using the auxiliary electrode 17 as amask, as in the foregoing embodiment, the aperture shape of theauxiliary electrode 17 may be substantially similar to the planar shapeof the recess 15A of the reflector layer 15.

Further, in the foregoing embodiment, the recess 15A of the reflectorlayer 15 may be formed by the isotropic etching using the auxiliaryelectrode 17 as a mask; however, the method for forming the recess 15Ais not limited thereto. For example, a combination of a plurality ofanisotropic etchings may also be adopted. As one example thereof, thereflector material may be etched in a thickness direction (verticaldirection), and thereafter may be etched in an intra-plane direction(lateral direction) to allow for formation of a structure similar tothat in the case of the isotropic etching. Further, other masks (such asa photoresist), instead of the auxiliary electrode as a mask, may alsobe used to perform etching.

Moreover, the material and thickness of each layer are not limited tothose listed in the foregoing embodiment and the application examples;each layer may be made of any other material with any other thickness.Further, it is not necessary for the display unit to include all of theabove-described layers; alternatively, yet another layer may also beincluded in addition to each of the above-described layers. It is to benoted that the effects described in the foregoing embodiment and theapplication examples are mere examples, and the effects of the presentdisclosure may be other different effects, or may further include othereffects.

It is to be noted that the disclosure may also have the followingconfigurations.

(1)

A display unit including:

a plurality of pixels each having a first electrode, an organic layer,and a second electrode in this order, the organic layer and the secondelectrode being provided on the first electrode, the organic layerincluding a light-emitting layer;

a reflector layer having a light-reflecting surface around each of thepixels; and

an auxiliary electrode that is provided on the reflector layer and isprojected from an upper end of the light-reflecting surface, theauxiliary electrode having a portion which is exposed from the organiclayer, the exposed portion being covered with the second electrode.

(2)

The display unit according to (1), wherein

the reflector layer has a plurality of recesses each having thelight-reflecting surface, the plurality of recesses facing therespective pixels,

the auxiliary electrode has a plurality of apertures that face therespective recesses, and

an aperture shape of each of the apertures in the auxiliary electrode issmaller than a shape of each of the recesses on upper end side in a planview.

(3)

The display unit according to (2), wherein the shape of each of therecesses is substantially similar to the aperture shape of each of theapertures.

(4)

The display unit according to (3), wherein the aperture shape of each ofthe apertures is smaller than the shape of each of the recesses.

(5)

The display unit according to any one of (1) to (4), further includinganother organic layer that is provided on the auxiliary electrode andcontains a material same as a material of the organic layer.

(6)

The display unit according to any one of (1) to (5), wherein thereflector layer contains silicon oxide (SiO_(x)), magnesium fluoride(MgF₂), lithium fluoride (LiF), a polyimide resin, an acrylic resin, afluorine resin, a silicone resin, a fluorine-based polymer, or asilicon-based polymer.

(7)

The display unit according to any one of (1) to (6), wherein theauxiliary electrode contains one or more of titanium (Ti), molybdenum(Mo), copper (Cu), and aluminum (Al).

(8)

The display unit according to any one of (1) to (6), wherein theauxiliary electrode contains one or more of indium-tin oxide (ITO),titanium oxide (TiO), indium-zinc oxide (IZO), indium-gallium-zinc oxide(IGZO), zinc oxide (ZnO), aluminum-added zinc oxide (AZO), fluorine(F)-added zinc oxide (ZnO:F), fluorine-added tin oxide (FTO), andfluorine-added silicon oxide (SiO₂:F).

(9)

The display unit according to any one of (1) to (8), wherein thelight-emitting layer included in the organic layer includes a singlelight-emitting layer or a plurality of stacked light-emitting layers.

(10)

A method of manufacturing a display unit, the method including:

forming a plurality of pixels each having a first electrode, an organiclayer, and a second electrode in this order, the organic layer and thesecond electrode being provided on the first electrode, the organiclayer including a light-emitting layer;

forming a reflector layer, the reflector layer having a light-reflectingsurface around each of the pixels;

forming, on the reflector layer, an auxiliary electrode that isprojected from an upper end of the light-reflecting surface; and

forming the organic layer and the second electrode after the forming ofthe reflector layer and the auxiliary electrode.

(11)

The method of manufacturing the display unit according to (10), whereinthe reflector layer is formed by performing isotropic etching that usesthe auxiliary electrode as a mask, after the auxiliary electrode isformed on the first electrode with a reflector material being providedtherebetween.

(12)

The method of manufacturing the display unit according to (10) or (11),wherein the second electrode is formed by a sputtering method or anatomic layer deposition (ALD) method.

(13)

An electronic apparatus including a display unit, the display unitincluding:

a plurality of pixels each having a first electrode, an organic layer,and a second electrode in this order, the organic layer and the secondelectrode being provided on the first electrode, the organic layerincluding a light-emitting layer;

a reflector layer having a light-reflecting surface around each of thepixels; and

an auxiliary electrode that is provided on the reflector layer and isprojected from an upper end of the light-reflecting surface, theauxiliary electrode having a portion which is exposed from the organiclayer, the exposed portion being covered with the second electrode.

This application is based upon and claims the benefit of priority of theJapanese Patent Application No. 2014-208116 filed with the Japan PatentOffice on Oct. 9, 2014, the entire contents of which are incorporatedherein by reference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations, and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1. A display unit comprising: a plurality of pixels each having a firstelectrode, an organic layer, and a second electrode in this order, theorganic layer and the second electrode being provided on the firstelectrode, the organic layer including a light-emitting layer; areflector layer having a light-reflecting surface around each of thepixels; and an auxiliary electrode that is provided on the reflectorlayer and is projected from an upper end of the light-reflectingsurface, the auxiliary electrode having a portion which is exposed fromthe organic layer, the exposed portion being covered with the secondelectrode.
 2. The display unit according to claim 1, wherein thereflector layer has a plurality of recesses each having thelight-reflecting surface, the plurality of recesses facing therespective pixels, the auxiliary electrode has a plurality of aperturesthat face the respective recesses, and an aperture shape of each of theapertures in the auxiliary electrode is smaller than a shape of each ofthe recesses on upper end side in a plan view.
 3. The display unitaccording to claim 2, wherein the shape of each of the recesses issubstantially similar to the aperture shape of each of the apertures. 4.The display unit according to claim 3, wherein the aperture shape ofeach of the apertures is smaller than the shape of each of the recesses.5. The display unit according to claim 1, further comprising anotherorganic layer that is provided on the auxiliary electrode and contains amaterial same as a material of the organic layer.
 6. The display unitaccording to claim 1, wherein the reflector layer contains silicon oxide(SiO_(x)), magnesium fluoride (MgF₂), lithium fluoride (LiF), apolyimide resin, an acrylic resin, a fluorine resin, a silicone resin, afluorine-based polymer, or a silicon-based polymer.
 7. The display unitaccording to claim 1, wherein the auxiliary electrode contains one ormore of titanium (Ti), molybdenum (Mo), copper (Cu), and aluminum (Al).8. The display unit according to claim 1, wherein the auxiliaryelectrode contains one or more of indium-tin oxide (ITO), titanium oxide(TiO), indium-zinc oxide (IZO), indium-gallium-zinc oxide (IGZO), zincoxide (ZnO), aluminum-added zinc oxide (AZO), fluorine (F)-added zincoxide (ZnO:F), fluorine-added tin oxide (FTO), and fluorine-addedsilicon oxide (SiO₂:F).
 9. The display unit according to claim 1,wherein the light-emitting layer included in the organic layer comprisesa single light-emitting layer or a plurality of stacked light-emittinglayers.
 10. A method of manufacturing a display unit, the methodcomprising: forming a plurality of pixels each having a first electrode,an organic layer, and a second electrode in this order, the organiclayer and the second electrode being provided on the first electrode,the organic layer including a light-emitting layer; forming a reflectorlayer, the reflector layer having a light-reflecting surface around eachof the pixels; forming, on the reflector layer, an auxiliary electrodethat is projected from an upper end of the light-reflecting surface; andforming the organic layer and the second electrode after the forming ofthe reflector layer and the auxiliary electrode.
 11. The method ofmanufacturing the display unit according to claim 10, wherein thereflector layer is formed by performing isotropic etching that uses theauxiliary electrode as a mask, after the auxiliary electrode is formedon the first electrode with a reflector material being providedtherebetween.
 12. The method of manufacturing the display unit accordingto claim 10, wherein the second electrode is formed by a sputteringmethod or an atomic layer deposition (ALD) method.
 13. An electronicapparatus including a display unit, the display unit comprising: aplurality of pixels each having a first electrode, an organic layer, anda second electrode in this order, the organic layer and the secondelectrode being provided on the first electrode, the organic layerincluding a light-emitting layer; a reflector layer having alight-reflecting surface around each of the pixels; and an auxiliaryelectrode that is provided on the reflector layer and is projected froman upper end of the light-reflecting surface, the auxiliary electrodehaving a portion which is exposed from the organic layer, the exposedportion being covered with the second electrode.